This invention relates to a method and apparatus for reporting dynamic product status information using Radio Frequency Identification Device (RFID) technology.
In storage units, such as a refrigerator, a medicine supply locker, or a warehouse, perishable items might exist that have expired or are near expiration. Examples of such are medical supplies, biological specimens or simply a carton of milk each with associated expiration dates. Similarly, containers might be near empty requiring the acquisition of new items to replenish the current stock. In general, the items in such a storage unit can be described by a set of measurable properties (e.g., expiration date, weight, temperature, etc.) which can be used to either determine further properties (e.g., expiration date can be a function of the temperature) or to initiate certain consumer actions (e.g., replenish stock, lower environmental temperature).
Inventory tracking systems using the RFID device have been identified by others. Related patents are U.S. Pat. Nos. 5,347,263, 5,280,159, 5,785,181, 5,611,051, 5,608,193. Best known is the EASY Pass System used at toll booths around the country. Such systems are based on passive devices, i.e. an ID is hard coded into an electronic tag which is interrogated using RFID technology when a vehicle passes by a toll booth. That ID is then used to charge the consumer account associated with the ID. However, there is a need for inventory tracking systems which incorporate active sensors to determine dynamic properties such as weight, temperature and expiration date information.
It is an object of this invention to determine and report on dynamic properties which can vary with environmental conditions of products using RFID technology. The current invention describes a method and an apparatus for determining dynamic properties of products and for transmitting these properties using RFID technology.
It is a more specific object of this invention to determine properties of perishable and consumable items and to transmit these properties using RFID technology. Such products include groceries and pharmaceutical products.
Accordingly, this invention includes an electronic tag reporting dynamic properties of a product, where the tag has at least one sensor for determining the dynamic properties of the product and transmitting the determined properties from the tag or storing the properties when the sensor is activated with a radio frequency identification (RFID) device.
This invention also provides for a method of reporting the dynamic properties of a product where the method comprises broadcasting an interrogation request, and activating a sensor by transmitting an activation signal from an RFID device, where the activation signal is transmitted in response to the interrogation request. Finally, sensory data or dynamic properties of the product are determined by the activated sensor.
Depending upon which sensor sub-units are integrated into the device or tag, different properties can be measured and sent to a digital assistant for off-line processing. The tag can be attached to the product by either the manufacturer or the consumer. For example, an electronic tag with a weight sensor is placed at the bottom of the container which is placed on a flat surface so that the device is capable of measuring the weight of the container. The digital assistant will periodically poll the tag on the container and retrieve information as to the weight of the container. In another example, an electronic tag with a temperature sensing device could be attached to a perishable item to determine its expiration date where the digital assistant will process the temperature measurements that are periodically sent to it.
The electronic tag could incorporate micro sensors that can be implemented with just a few micro electrical components that can fit onto a single chip. Further, these micro sensors are readily available on the market at low cost.